1. Field of the Invention
The present invention relates to pressurized gas lines, particularly flammable natural gas lines provided by utilities. More particularly, the present invention relates to an automatic shut-off which is activated upon a catastrophic break in the gas line.
2. Description of the Prior Art
Natural gas has increasingly become an indispensable service for many industrial, commercial and residential utility customers. In order to supply natural gas from the utility to the customer, the utility pressurizes the natural gas and sends it out along a distribution system that includes gas mains. At the customer, a gas line intercepts the gas main, wherein the gas line includes a gas meter and gas pipes.
Natural gas is an extremely efficient and clean source of energy, but must be used with care since it is extremely flammable, indeed explosive. Natural gas is odorless, and in recognition of the danger that leaking natural gas poses, gas utilities scent the natural gas so that a customer can smell leaking natural gas.
Particularly problematic are situations in which the gas line suffers a catastrophic breakage, wherein natural gas rushes out of the broken gas pipe and creates an immediate danger of explosion. Examples of situations which can arise in everyday life that could result in a catastrophic pipe break include motor vehicles accidentally striking a building at the gas line, or natural disasters such as tornadoes, hurricanes or earthquakes, which destroy the building in the vicinity of the gas line. Since in such instances massive amounts of natural gas can collect very rapidly, a catastrophic breakage of a gas line is dangerous for the building occupants, as well as utility workers.
Accordingly, what is needed in the art is a gas line shut-off which is automatically actuated in the event of a catastrophic break of a gas line.